Certain first generation fusion reactors are fueled by a fixed mixture of deuterium (D) and tritium (T) to produce helium residue or ash in the residual DT fuel mixture or effluent. Elimination of the helium necessitates removal of large quantities of the residual DT fuel mixture. After separation of the helium, it is desirable to separate the hydrogen isotopes and to reintroduce them separately back into the reactor. The present invention deals with the problem of separating the hydrogen isotopes.
Proposals have been made in the prior art for the use of several different hydrogen isotope separation methods, in connection with fusion reactors. Such methods include cryogenic distillation, gas chromatography, and thermal diffusion.
Cryogenic distillation separates the different hydrogen isotopes at their boiling points, approximately 20 degrees Kelvin. While cryogenic distillation is presently considered by some scientists to be the most practical isotope separation method for a fusion reactor, such method suffers from the problem that it requires a very large tritium inventory, greater than 100 g (10.sup.6 Ci). Also, the expected cost of a cryogenic distillation separator is great, amounting to several millions of dollars.
As possible alternatives, gas chromatography and thermal diffusion have been proposed. The difficulty with these alternative methods is that the throughput is small (approximately 0.1 Torr liters/sec).